1. Field of the Invention
The present invention relates generally to an ink cartridge refill system for inkjet printers and method of refilling ink cartridges using the system.
2. Description of the Related Art
Most users of inkjet printers prefer to refill and reuse ink cartridges rather than use new ink cartridges because the new ink cartridges are expensive. In an effort to satisfy the above-mentioned preference of the users of inkjet printers, some ink cartridge manufacturers have proposed and marketed ink cartridges that are provided with refill nozzles to allow users to refill ink cartridges through the refill nozzles.
Korean Patent Laid-open Publication No. 10-2003-69596, which was published on Aug. 27, 2003, discloses a conventional ink cartridge refill system that is configured as a refill system to be used by someone in the business of refilling customers' ink cartridges. The above-mentioned refill system is constructed such that an ink cartridge is loaded in a cartridge loading unit and is refilled with ink simply by manipulating a control switch of the cartridge loading unit.
Herein below, the conventional ink cartridge refill system 100, disclosed in the above-mentioned Korean Patent Laid-open Publication Gazette, will be described with reference to FIGS. 1 through 4.
As shown in FIG. 1, the conventional ink cartridge refill system 100 includes a plurality of cartridge loading units 110 in each of which an ink cartridge (not shown) to be refilled with ink is loaded. The refill system 100 also includes a plurality of ink reservoirs 120 to inject ink, temporarily contained therein, into ink cartridges loaded in the cartridge loading unit 110 through a plurality of ink injection hoses 101, and an ink tank 140 which stores ink therein and supplies ink to the ink reservoirs 120 through a plurality of ink supply hoses 102. Furthermore, a plurality of pressure cylinders 130 is connected to an air compression pump 150 through a plurality of air hoses.
The above-mentioned refill system 100 is operated as follows. When a control switch 104 is turned on after completely loading an ink cartridge into a cartridge loading unit 110, pressurized air from the air compression pump 150 is introduced into the pressure cylinders 130 associated with the cartridge loading unit 110, so that air pressure acts on the pistons (not shown) in the cylinders 130. Thus, the interior of the ink reservoir 120 is compressed, so that ink from the ink reservoir 120 is injected into the loaded ink cartridge. When the ink cartridge has been completely refilled with ink, the pressure in the cylinders 130 is reduced, causing the pressure in the ink reservoir 120 to be reduced. As the pressure in the ink reservoir 120 becomes reduced as described above, ink is newly supplied from the ink tank 140 into the ink reservoir 120.
In the refill system 100 shown in FIG. 1, three ink supply hoses 102 and three ink injection hoses 101 are provided to supply or inject different colors of ink, which are cyan ink, magenta ink and yellow ink. A one-way valve 101a, 102a is installed in each of the three ink injection hoses 101 and three ink supply hoses 102, thus preventing ink from flowing in a reverse direction while the ink flows from the ink reservoir 120 into the loaded ink cartridge or from the ink tank 140 into the ink reservoir 120. Each of the chambers of the ink tank 140 and the ink reservoir 120 is partitioned into three storage chambers, thereby separately containing the three different colors of ink therein. Furthermore, the three pressure cylinders 130 are provided to respectively communicate with the three storage chambers of the ink reservoir 120.
As shown in FIGS. 2 and 3, each of the cartridge loading units 110 of the refill system 100 comprises a body 111 in which an ink cartridge 1 is seated, an ink injection part 112 which comes into close contact with the nozzles 2 of the cartridge 1, and a cartridge holding part 120 which is placed at the opposite end from the nozzles 2 of the cartridge 1. The cartridge holding part 120 is configured such that, when a handle 121 is rotated upwards or downwards around a joint, the rotating motion of the handle 121 is converted into rectilinear motion of a sliding bar 122 by a link 123, so that the sliding bar 122 linearly moves forwards or rearwards. A cushion member 124 is mounted to the front end of the sliding bar 122, thus protecting the ink cartridge 1 from being impacted when the cartridge 1 is loaded into the cartridge loading unit 110.
The ink injection part 112, which comes into close contact with the nozzles 2 of the ink cartridge 1, is provided with a plurality of ink injection holes 113 that respectively correspond to the nozzles 2 of the cartridge 1. The ink injection holes 113 are connected to the ink injection hoses 101 by means of a plurality of connectors 115. As shown in FIG. 4, three different colors of ink, which are cyan ink, magenta ink and yellow ink, respectively supplied through the three ink injection holes 113, are injected into the ink cartridge 1 via the three nozzles 2.
Although the above-mentioned ink cartridge refill system is advantageous in that the system refills an ink cartridge in response to simple operation of the control switch after an ink cartridge has been loaded into a cartridge loading unit, the refill system is problematic as follows. The problems experienced in the conventional ink cartridge refill system will be described herein below with reference to FIGS. 1 through 4.
When ink is injected into an ink cartridge through the nozzles of the cartridge using air pressure in the manner disclosed for the above-mentioned refill system 100, the inner pressure of the cartridge 1 has increased to a level higher than atmospheric pressure at the time that the ink cartridge refill process has been completed, due to both pressurized air and ink having been injected into the cartridge 1. Thus, if the ink cartridge 1 which has been completely refilled with ink is directly detached from the cartridge loading unit 110, the ink may be ejected by the pressure of the cartridge 1 to the atmosphere through the nozzles 2. The ejected ink messes up both the nozzles 2 and the cartridge loading unit 110.
Furthermore, the ink remaining in the gap between the nozzles 2 and the ink injection part 112 flows down and contaminates the cartridge loading unit 110.
The ink cartridges for inkjet printers have been typically classified into two types: sponge type and pack type. Particularly, the pressure of the pack-type ink cartridges must be regulated after refilling the cartridges. The regulation of the pressure of the pack-type cartridges is made necessary by the fact that an excessive amount of ink may be discharged from the cartridge and deteriorate printing quality when the cartridge is first used, as well as the fact that the ink may be ejected under pressure at the time that the refilled cartridge is detached from the cartridge loading unit 110.
In an effort to solve the above-mentioned problems, it is necessary to expel predetermined small amounts of air and ink from a refilled cartridge and to regulate the inner pressure of the cartridge when the ink cartridge refill process has been completed. However, the above-mentioned conventional ink cartridge refill system is not configured to regulate the inner pressure of ink cartridges after refilling the cartridges.
Furthermore, the above-mentioned ink cartridge refill system is not compatible with a variety of ink cartridges having different sizes and different capacities. Described in detail, when it is desired to refill an ink cartridge having a size and capacity different from those of a previously refilled cartridge, a user must change the length of the sliding bar 122 before turning on the control switch, so that the sliding bar 122 supports the cartridge with an appropriate biasing force. Furthermore, to inject an appropriate amount of ink into an ink cartridge loaded in the cartridge loading unit, it is necessary to adjust the strokes of the pistons in the pressure cylinders 130 by adjusting a plurality of ink supply control units 131 provided on the cylinders 130.
Because the above-mentioned conventional refill system 100 is provided only with a one-way valve 101a in each of the ink injection hoses 101 in an effort to prevent ink from flowing in a reverse direction toward the ink reservoir 120, small amounts of ink inevitably remain in the ink injection holes 113 after an ink cartridge has been completely refilled with ink by the refill system. Thus, when the cartridge loading unit 110 having the ink injection holes 113 in which ink remains is not used for a lengthy period of time, the quality of ink remaining in the ink injection holes 113 is reduced. When the ink having the reduced quality is injected into a cartridge during a refill process, the printing quality is reduced and, furthermore, the nozzles of the cartridge may become blocked.
Typically, ink is not completely used but some ink may remain in an ink cartridge 1, so that it is sometime required to completely empty the cartridge 1 prior to refilling the cartridge 1. However, the conventional ink cartridge refill system 100 is configured such that the system 100 merely injects ink into cartridges 1 and does not automatically empty the cartridges. Thus, the user of the refill system 100 must manually empty the cartridges 1 prior to refilling the cartridges 1, so that it is inconvenient for the user to use the system 100.